pppoe users disconnects sevraltimes

My one 2.4 Horizontal sector disconnects my pppoe users. Where would the problem most likely be? on the sector? Wirelesscard? or on the rb?
The other 2.4 runs with no problems on the same board so I doubt its the RB

Setup is RB433AH
R52hn card
RBos 4.11

If you need any other info to help me please let me know.

Thanks